This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Livingston, R. S. Articles by Scheffer, R. P. Search for Related Content PubMed PubMed Citation Articles by Livingston, R. S. Articles by Scheffer, R. P. Agricola Articles by Livingston, R. S. Articles by Scheffer, R. P.

Articles

Conversion of Helminthosporium sacchari Toxin to Toxoids by -Galactofuranosidase from Helminthosporium¹

Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824-1312

Helminthosporium sacchari produces a host-selective toxin and structurally related nontoxic compounds, here referred to as `toxoids.' Toxin and the three toxoids were each isolated to a high level of purity and were hydrolyzed under acidic conditions. The released galactose was measured by a galactose oxidase/peroxidase assay. Toxin was found to contain four units of galactose per molecule, as previously reported. Toxoids I, II, and III contained one, two, and three units of galactose, respectively. In cultures of the fungus, toxin concentration peaked at 3 weeks, followed by a rapid decline; as toxin levels fell, the total amount of toxoids increased. An enzyme with -galactofuranosidase activity was found in small amounts in the cultures of H. sacchari; the enzyme converted toxin to the toxoids in vitro. -Galactofuranosidase was previously known from very few micro-organisms; therefore, several pathogenic Helminthosporia and other fungi were tested for production. -Galactofuranosidase activity in culture filtrates and mycelia of H. victoriae, H. maydis, H. carbonum, and H. turcicum was much greater than in filtrates and mycelium of H. sacchari. More work is needed to determine the significance of enzyme production by these fungi. No -galactofuranosidase was evident from Fusarium oxysporum and Cladosporium cucumerinum.

This article has been cited by other articles:

				M. Kodama, M. S. Rose, G. Yang, S. H. Yun, O. C. Yoder, and B. G. Turgeon The Translocation-Associated Tox1 Locus of Cochliobolus heterostrophus Is Two Genetic Elements on Two Different Chromosomes Genetics, February 1, 1999; 151(2): 585 - 596. [Abstract] [Full Text]